function unselectall()
{
    if(document.myform.chkAll.checked){
	document.myform.chkAll.checked = document.myform.chkAll.checked&0;
    } 	
}

function CheckAll(form)
  {
  for (var i=0;i<form.elements.length;i++)
    {
    var e = form.elements[i];
    if (e.Name != "chkAll"&&e.disabled==false)
       e.checked = form.chkAll.checked;
    }
  }